ORLANDO, Fla. — Pieces of a tiny skeleton found in swampy woods can tell investigators one thing: Missing 3-year-old Caylee Anthony was killed. What they can’t help explain, authorities said Friday, is how or when she died.

DNA tests conducted on remains found by a utility worker last week less than a half-mile from where the child lived matched Caylee’s genetic profile, a county medical examiner said. But the only clue they give about her death is that her bones didn’t suffer trauma, said Orange County medical examiner Dr. Jan Garavaglia.

“Bottom line is, folks, no child should have to go through this,” Orange County Sheriff Kevin Beary said.

The discovery of the child’s remains came after months of searches, twists and turns in the investigation. Caylee’s mother, 22-year-old Casey Anthony, was indicted in October on first-degree murder and other charges, even though no body was found. She has insisted that she left the girl with a baby sitter in June, but she didn’t report her missing until July.

A search team said they did not check the wooded area sooner because it was under water from the summer’s heavy rains. But the utility worker who provided the tip, Roy Kronk, said he had contacted the sheriff’s office in August to report that he had seen “something suspicious, a bag, in the same area.”

The sheriff’s office said he first called Aug. 11 to report the bag. A deputy responded but didn’t find anything and was unable to locate him. Kronk called a crime hot line the following day and the information was passed on to the sheriff’s office criminal investigation division. On Aug. 13, he called the sheriff’s office a third time. He met a deputy, but authorities cleared the area as a place of interest in the search a short time later.

Violent police encounters in California last year led to the deaths of 157 people and six officers, the state attorney general’s office said Thursday in a report that provides the first statewide tally on police use-of-force incidents.